Deck 6: Solids

Question 1

Which of the following statements describe properties of metallic solids? Please select all that apply.

A) good thermal conductivity
B) high density
C) brittle
D) good electrical conductivity

Answer 1

A, B, D

Question 2

Ionic solids are held together with __________ interactions.

Answer 2

electrostatic

Question 3

Match the material with the bonding type.
-platinum (Pt)

A) metallic
B) molecular
C) covalent
D) ionic

Answer 3

A

Question 4

Match the material with the bonding type.
-N₂O

A) metallic
B) molecular
C) covalent
D) ionic

Question 5

Match the material with the bonding type.
-S

A) metallic
B) molecular
C) covalent
D) ionic

Question 6

Match the material with the bonding type.
-SrF₂

A) metallic
B) molecular
C) covalent
D) ionic

Question 7

A crystalline solid demonstrates long-range order which persists over distances much greater than the bond length between the atoms. It is possible to predict the position of every atom from those given in the unit cell.

Question 8

The structure of C₆₀ is analogous to the stitching on a European football and is shown in the diagram below. Each carbon lies on the surface of a sphere and the carbon is sp³ hybridized?

Question 9

Silicon dioxide exists as different polymorphs e.g. quartz and cristobalite. When silicon dioxide is melted and quenched (rapidly cooled), it forms an _______ structure known as a glass.

Question 10

A magnetic levitation train uses the Meissner effect to propel the train along magnetic rails. Which of these facts relating to superconductors are true. Please select all that apply.

A) Superconductors are diamagnetic.
B) No matter the temperature, superconductors exhibit the Meissner effect.
C) Electrons move in pairs through the lattice.
D) The Meissner effect occurs at low temperature when the superconductor is below its critical temperature.

Question 11

The structure with repeat sequence ABCCABCCABCCABC is close-packed.

Question 12

A body centred cubic unit cell is close-packed.

Question 13

-tungsten crystallises with a body centred cubic structure where the length of the unit cell is 3.150 Å. Use the diagram to calculate the radius of a tungsten atom. (Hint: The radius of the atom is just half the distance between the two closest atoms.)

A) 2.692 Å
B) 1.136 Å
C) 1.346 Å
D) 1.575 Å

Question 14

A lattice point on the edge of a cubic unit cell is worth one quarter of a lattice point

Question 15

A semiconductor has which of the following properties? Please select all that apply.

A) A filled conduction band.
B) A significant but small band gap.
C) A filled valence band.
D) Conductivity that falls as the temperature falls.

Question 16

What is the formula of a compound based on cubic close packing where one quarter of the tetrahedral holes (T) are filled in a lattice made of lattice points of type A. What is the coordination number of the filled holes and the lattice points? Please select all that apply.

A) Formula A₂T
B) Coordination number of the lattice point would be 2 and the filled hole would be four.
C) Formula AT₂
D) Coordination number of the lattice point would be 4 and the filled hole would be four

Question 17

Li₂O crystallises with the antifluorite structure where the positions of the cations and anions are in the opposite positions to the structure observed for fluorite. What are the coordination numbers of the lithium and oxygen ions?

A) Lithium is four coordinate and oxygen is six coordinate.
B) Lithium is four coordinate and oxygen is eight coordinate.
C) Lithium is eight coordinate and oxygen is four coordinate.
D) Lithium and oxygen are both six coordinate.

Question 18

Lattice point counting for sphalerite shows that the structure contains ___ Zn/S ions.

Question 19

The coordination number of iodine in cadmium iodide is six.

Question 20

There is no structural analogue of CaF₂ in hexagonal close packing (fill all tetrahedral holes).

Question 21

The structure of the perovskite (calcium titanate) is given below. What is the coordination number of the two cations? Please select all that apply.

A) Ca is 12 coordinate
B) Ti is 12 coordinate
C) Ti is 6 coordinate
D) Ca is 6 coordinate

Question 22

The ionic radius of an atom can be measured by X-ray diffraction.

Question 23

Magnesium oxide crystallizes with the sodium chloride structure. Magnesium oxide obeys the radius ratio rule for this structure.

Question 24

Use the following data to construct a thermochemical cycle for the formation of ZnS from its elements and use the cycle to calculate the enthalpy of formation of ZnS.
Zn (s)  Zn (g) 130 kJ mol^-1
Zn (g)  Zn⁺ (g) 906 kJ mol^-1
Zn⁺ (g)  Zn²⁺ (g) 1733 kJ mol^-1
ZnS (s)  Zn²⁺ (g) + S^2- (g) 3048 kJ mol^-1
S (s)  S (g) 233 kJ mol^-1
S (s)  S^- (g) -200 kJ mol^-1
S^- (s)  S^2- (g) 456 kJ mol^-1

A) 200 kJ mol^-1
B) -200 kJ mol^-1
C) 33 kJ mol^-1
D) 2848 kJ mol^-1

Question 25

Match the value of Born exponent with the appropriate compound. given that the Born exponent values for the individual ions are Be²⁺ = 5, F^- = 7, Zn²⁺, S^2- and Cl^- = 9, Rb⁺ = 10, Cs⁺ = 12 respectively.
-ZnS

A) 9.0
B) 10.5
C) 6.33
D) 9.5

Question 26

Match the value of Born exponent with the appropriate compound. given that the Born exponent values for the individual ions are Be²⁺ = 5, F^- = 7, Zn²⁺, S^2- and Cl^- = 9, Rb⁺ = 10, Cs⁺ = 12 respectively.
-CsCl

A) 9.0
B) 10.5
C) 6.33
D) 9.5

Question 27

Match the value of Born exponent with the appropriate compound. given that the Born exponent values for the individual ions are Be²⁺ = 5, F^- = 7, Zn²⁺, S^2- and Cl^- = 9, Rb⁺ = 10, Cs⁺ = 12 respectively.
-BeF₂

A) 9.0
B) 10.5
C) 6.33
D) 9.5

Question 28

Match the value of Born exponent with the appropriate compound. given that the Born exponent values for the individual ions are Be²⁺ = 5, F^- = 7, Zn²⁺, S^2- and Cl^- = 9, Rb⁺ = 10, Cs⁺ = 12 respectively.
-RbCl

A) 9.0
B) 10.5
C) 6.33
D) 9.5

Question 29

Use the Born Lande equation to calculate the lattice energy of MgO given that r = 210.5 pm.

A) 7914 kJ mol^-1
B) 3957 kJ mol^-1
C) 4617 kJ mol^-1
D) 989 kJ mol^-1

Question 30

Use the Kapustinskii equation to estimate the lattice enthalpy for KBr given that the ionic radii are 138 and 196 pm for K⁺ and Br^- respectively.

A) 646 kJ mol^-1
B) 323 kJ mol^-1
C) 2584 kJ mol^-1
D) 46 kJ mol^-1

Question 31

Iron and cobalt both have similar low electronegativities. The predicted structure based on this information is an alloy.